Air compressor



July 17, 1928. 1,677,539

' H. P. WOLLMAN AIR COMPRESSOR Filed on. "a, '1927 2 Sheets-Sheep 1 I an-uqntoz 2 H B No Imam as, Y

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Jul 17, 1928. 1,677,539

H. P. WOLLMAN AIR courxsssoa I v Filed Oct. 6. 1927 2 Sheets-Sheet 2 5] 111mm toz Patented July 17, 1928.

UNITED STATES 1,677,539 PATENT OFFICE.

HARRY}, WOULI IAN, OF WASHINGTON, DISTRICT OF COLUMBIA.

- AIR COMPRESSOR.

Application filed October 6,1927. Serial No. 224, 4ea.

' The present invention is directed to improvements in air compressors.

, The primary object of the invention is to ill provide a device of this character'which is simple in construction, compact, and one which will produce a maximum amount of compressed air with minimum working cost.

Another object of the invention is to provide a compressor includin a plurality of f radially disposed cylinders in which are reciprocally mounted pistons, there being a power driven eccentric for successively reconsist of upper and lower sections 5 and-6,'

cip'rocating the pistons for compre sing air for discharge into a "storage tank.

While the device is primarily designed for operating excavatingshovels, it w1ll be of course understood that it is not necessarily limited to such use since it is another aim of the invention to provide a compressor which. may be made in various sizes for any use wherein compressed air is used as a motive fluid.

With these and other objects inview this invention resides in the novel features of construction, formatiomcombination and arrangement ofparts to be herelnafter'more fully described, claimed and illustratedin the accompanying clrawing,'in WlllCll,-' Figure 1 is a vertical sectional view through the device. a Figure 2'is'asimilar View, taken at right angles to Figure 1. a

Figure 3 is a fragmentary enlarged detail sectional yiew of one of the pistons and cylinders.

Referring to the drawings, 1 designates a casing having fixed'and removable heads 2 and 3 provided with. alfn'ed bearings 4 which arms 12 carried by the base 13 which may be bolted to a suitable foundation. Spacing. sleeves 14 are engaged upon the shaft 9 and serve to hold said shaft against endwise movement. To one end of the shaft 9 is lined a gear or pulley 14 through which rotary movement is imparted to the shaft from any suitable source, there being a fan 15 fixed to the opposite end of said shaft which not only serves to maintain the device in a cool state but also serves as a fly wheel.

The casing 1 has communicating therewith a plurality of cylinders 16, in this instance four being shown, and in which are mounted for reciprocating pistons 17. These cylinders consist of inner and-outer sections 18 and 19, the latter having heat dissipating \vebs 20. The inner sections are bolted to the casing 1, as at 21, and to the outer flanged ends thereof are' bolted the inner ends of the. sections 19, and it is in these sections that the pistons 17 ireciprocate. The sections 19 are of less diameter than the sections 18 in order to provide annular shoulders 22, the purpose of which will be later explained.

Theinner ends of the pistons are provided with heads 23 adapted to slide in the sections 18 and are provided with shoulders 24 opposed to the shoulders 22. Encircling the piston; 17 are coil springs 25 which have lheir'respective terminals engaged with the shoulders 22 and 24, said springs; serving to urge the pistons 17 inwardly in order to maintain the rollers 26 yieldably engaged in the groove 11 of the ececntric 10, said rollers being'journaledon shafts 27 which are supportled by the spaced extensions 28 of said heac s.

The sections 19 of thecylinders have heads- 29 bolted thereon and fitted thereto are cages 30 in which are mounted "alves 31 which outstroke of the pistons and to disengage the seats upon the instroke of the pistons, there being coil springs 33 engaged with the stems of the valves to pbsitlvely seat-said valves. 1' Leading from the head's 29 are branch pipe assemblies 35 and through which air tlu are adapted to close the seats 32 upon the v underpressure from the cylinders is conducted to the manifold 36 and from thence through a pipe 37 which leads "to astorage tank. The pipe assemblies 35 and the pipe 37 'are provided, respectively, with gheck valves 38 and 39 to prevent back-flow of the fluid. The top piston and the opposed horizontal pistons are provided with bores 40 which-open at-their inner ends in the heads and are provided with perforations 41 to permit oil contained in the casing 1 to enter the cylinders to secure proper lubrication. The lower piston is hollow, but is closed at its inner end, as at'42 to prevent oil filling the cylinder in which it works. The head 23 of this piston as well as the heads of the remaining pistons are provided with grooves 43 to permit oil to pass into the cylinders to aid in "the lubrication thereof.

Bricl'iygthe operation is as follows: Rotary movement being imparted to the shaft 9 will rotate the eccentric which will cause" the pistons to successively reciprocate in the cylinders. Obviously on the instroke of the pistons the valves will be unseated to permit air to be drawn into the cylinders,

the outstroke of the pistons compressing the air drawn thereinto and discharging the same through the pipe assemblies into the manifold 36 and from thence to the storage tank, not shown, through the pipe 37. Obviously, the rapid rotation of the shaft 9 will cause the pistons to successively draw in air and compress the same.

The fact that the rollers 26 engage in the groove 11 of the eccentric will preclude any possibility of the pistons rotating during their reciprocation.

Having thus described the invention, I claim: r

1. In a compressor, the combination of a casing, a driving eccentric rotatable in the casing, cylinders carried by the casing and communicating with the interior thereof,.

pistons reciprocable in the cylinders, said cylinders and pistons having opposed shoulders, springs encircling the pistons and having their respective terminals engaged with the shoulders to normally urge the pistons inwardly towards the eccentric, and driving means between the pistons and eccentric, as and for the purpose set forth.

2. In a compressor, the combination of a casing, a driving eccentric rotatable within the casing and having a peripheral groove, radially disposed cylinders carried by the casing and communicating with the interior thereof, pistons reciprocable in the cylinders, rollers associated with the pistons and means for yieldably holding the rollers-in said groove.

3. In'a compressor, the combination of a casing, a driving eccentric rotatable in the casing, radially disposedoylinders carried by the casing and communicating with the interior thereof, said cylinders including inner and outer sections varying in diameter, pistons reciprocable in the outer sections and having heads reciprocable in the inner section, yieldable means interposed between the outer sections and heads for urging the heads and pistons inwardly towards the eccentric, and driving engagement between the eccentricand heads for reciprocating the pistons, as and for the purpose set, forth.

4. In a compressor, the combination of a casing, an eccentric mounted for rotation in the casing, radially disposed cylinders carried by the casing, pistons reeiprocable' in the cylinders and including heads which extend into the casing, said heads having rollers e'arried thereby for contact with the periphery of the eccentric to impart reciprocatory movement to the pistons in one direction, during rotation of the eccentric, springs mounted in the cylinders for urging the pistons in a reverse direction, said heads having grooves therein for conducting oil from the casing to the cylinders. I

5.- In a compressor, the combination of a casing, cylinders carried by the casing and consisting of inner and outer-sections varying in diameter, pistons movable in the outer section, heads carried by the pistons and movable in the inner sections, the inner ends of the outer sections constituting shoulders, springs encircling the pistons and having their respective terminals engaged with the shoulders and heads for urging the pistons inwardly toward the eccentric, and driving means between the heads and eccentric, as and for the purpose set forth.

In testimony whereof I affix my signature.

HARRY P. WOLLMAN. [n 5. 

